Gaseous electric discharge device



Feb. 11, 1936. E. G. DoRGl-:Lo

GASEOUS ELECTRIC DISCHARGE DEVICE Filed April 16, 1935 INVENTOR Mun/WZPatented Fete@ M9 EQ@ narran stares access@ desirous penetrare meenemennutren Eduard Gi., Bargeld, Eindhoven, Netherlands, signor to GeneralEimtnc Company, a corpo@ ration of New York Application Aprill 11.6,i935, Seriali Nit. llttd? lin the Netherlands Aprill i9, 193@ 2Cia-sims.

"idle present invention relates to gaseous electric discharge devicesgenerally and more particularly the invention relates to starting andoperating circuits for such devices.

5, I have observed that in illuminating systems comprising a pluralityof transformers having the primaries thereof connected in series acrossthe terminals of an alternating current source and the secondariesthereof connected to a gaseous l@ electric discharge lamp device of thetype having thermionic electrodes and operating with an elevatedcontainer temperature, such as sodium vapor lamps, the number of lamp'swhich can be successfully started and operated on the voltage yg of thecurrent source is limited. When the number of lamps is too large thethermionic electrodes thereof arenot heated at all or are heated veryslowly tothe temperature most favorable for theecient operation of thelamp. The lamps thus require an appreciable time to attain thetemperature at which they operate at maximum efficiency and perhaps donot reach such tempera- ,ture at all.

The object of the present invention is to increase the number of gaseouselectric discharge vapor lamps which can be successfully started andoperated in circuits of the above type. A further object of theinvention is to shorten the starting period of such lamps in such;circuits. Still fur- 3o ther objects and advantages attaching to thedevice and to its use and operation will be apparent to those skilled inthe art from the following particular description.

The invention attains its objects by connecting 3d a choke coil inparallel with a number of transformer primaries and in series with theother transformer primaries in the circuit. When potential is applied'tothe above described circuit a higher current flows through thetransformer pri- '40 maries connected in series with the choke coil thanwould ow therethrough'in the absence" of said .choke coil. When theelectrodes are of the type having a heater foi` the electron emittingmaterial, which heater is connected across a few 45 turns of thetransformer secondary, the higher transformer current rapidly heats theelectrodes to the electron emitting, discharge supporting temperaturethereof and the lamp container is rapidly raised to the elevatedtemperature at 50 which the lamp operates eciently. When the electrodesare of the type wherein the electron emitting material is heateddirectlyl by the discharge incident thereat and the discharge currentflow therethrough the higher transformer -55 current causes a higherdischarge current between the electrodes, which are cold when thecircuit is closed, andthe electrodes are rapidly heated to the electronemitting, discharge supporting teinperature thereof and the lampcontainer is rapidly raised to the velevated temperatures at which the 5lamp operates emciently. `when the operating current is nowing throughthese lamps the potential difference between the ends or" the chokecoilis such that current ow through the 4primaries of the transformersconnected in parallel w with said choke-coil is sucient to rapidly heatthe thermionic electrodes of the lamps connected to the secondaries ofsaid transformers and the containers of the lamps to the temperature atwhich said lamps operate efficiently. 5

In the drawing accompanying and forming part of this specication'anembodiment of the invention is shown schematically.

Referring to the drawing the new and, novel illuminating systemcomprises a plurality of 2@ gaseous electric discharge lamp devices iand 2 eachV of which comprises an elongated container having a pair ofelectrodes tl sealed therein and mounted at opposite ends thereof and agaseous atmosphere therein, such as neon and sodium va- 25 por. Aquantity of sodium is introduced into the container of the lamp duringthe manufacture thereof and is the source of the sodium vapor. Saidelectrodes 3 are electron emitting when heated and each of saidelectrodes 3 comprises a 30 heater lament, such as a tungsten or anickel filament, coated or impregnated with an electron emittingmaterial, such as barium and barium oxide. When desired the heaterfilament is wrapped around a bar or rod of electron emitting material.For purposes of simplicity or" illustration the lamps i and 2 are shownschematically in the drawing. Since the structure of this type of lampis now Well known further description and illustration thereof has beenomitted.

Each of the discharge vlamps i connected to the secondary d of atransformer 3, 6 and each of the lamps 2 is connected to the secondary 5of a transformer 5, l. The primaries 6 and l of said transformers 4, 6and 5, l are connected in series 45 across the terminals B of analternating current source. The heating current for each of saidelectrodes 3 is supplied by a few turns at the end of the secondary 4 or5 of said transformers 4, 6 or 5, l, respectively. The alternating`current; source for the above described circuit is, preferably, aconstant current transformer. A choke coil 9 is connected in parallel tothe primaries lV and in series with the primaries 6 with respect to thecurrent source 8.

charge supporting temperature and the dis-` charge in the gas betweentheelectrodes 3 in each of said lamps I starts shortly after potential isapplied to the circuit. The lamp container is rapidly heated by said gasdischarge to the vaporization temperature of the sodium and the lamp isan eicient source of sodium vapor light.

When the operating discharge current is flowing in the lamps I thepotential difference between the ends of the choke coil 9 isconsiderably greater than during the starting period of said lamps I.The size of the choke coil 9 with relation to the number of lamps 2 issuch that the potential difference between the ends of the choke coil 8after the lamps I have started is suilicient to start the lamps 2 intooperation.

When all the lamps I and 2 have been started into operation the currentow through the tubes 2 is slightly lower than the current flow throughthe lamps I, due to the choke coil 9. However, since the current throughsaid choke-coil 9 lags about with respect to the current iiow throughthe lamps 2, the difference between the lamp 2 current and the lamp Icurrent is so small as to be insignicant and it is not necessary todisconnect the choke-coil 8 after the lamps have been started intooperation.

. When desired, the electrodes 3 are of the type which are heated to andmaintained at an electron emitting, discharge supporting temperature bythe discharge current. In this case the high current flowing through theseoondaries 5 causes a more intense glow-discharge current between theelectrodes 3 which rapidly brings the lamps 2 to their elevatedoperating temperature.

While I have shown and described and have pointed out in the annexedclaims certain novel features of the invention, it will be understoodthat various omissions, substitutions and changes in the forms anddetails of tle device illustrated and in its use and operation may bemade by those skilled in the art without departing from the broad spiritand scope of the invention, for example, the transformers 4, 6 and 5, 1are autotransformers, when desired, and the gaseous atmosphere of thelamps consists of or comprises other metal vapors, such as mercuryvapor,cad mium vapor, magnesium vapor, or thallium vapor.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:-

l. An illuminating system comprising in combination a current source, aplurality of gaseous electric discharge lamps, a plurality oftransformers therefor, the primaries of said transformers beingconnected in series across the terminals of said current source and achoke coil connected in series with some of said transformer primariesand in parallel with the others of said transformer primaries withrespect to said current source, said choke-coil starting said lampsconnected to the transformers connected in parallel thereto after saidlamps connected to said transformers connected in series therewith havestarted.

2. An illumina-ting system comprising in combination a constant currentsource, a plurality of gaseous electric discharge lamps, a plurality oftransformers therefor, the primaries of said transformers beingconnected in series across the terminals of said current source and achoke coil connected in series with some of said transformer primariesand in parallel with the others of said transformer primaries withrespect to said current source, said choke-coil starting said lampsconnected to the transformers connected in parallel thereto after saidlamps connected to said transformers connected in series therewith havestarted.

EDUARD G. DORGELO.

